Going to be using factory ammo, probably 150, 165 & 180g.

Thanks, Rob

For 150-168 a 1 in 14 would be fine, but if you want to shoot 180s like you say, get the 1 in 10. I have a 1-10 in my 308 and it works great for bullets of 150grns all the way up to 220grns.

Rob,

My .308s are all 12" twist, and they handle any 180 grain bullet (even the long monolithics).

If you want to go up to 200 or 220 grains you would probably need the 10" twist usually used in the .30-'06. It is actually the length of the bullet that you worry about, of course weight goes up with length too.

jim dodd

The most important thing to consider is will the rifle be used for target or game/tactical situations. The twist rate does more than just stabilize the bullet; such as the rotational velocity and terminal ballistic effects. Generally the faster twist will create a better mushroom and more rapid energy transfer ALL OTHER THINGS EQUAL AND CONSIDERED. So first consider what bullet weights you would consider best for your applications, then decide on which will best suit those criteria. I have found that for the most part the 150 and 165/8 grain weights to be the best all around performers in this caliber. Only 38 years of experience on this though...

Some manufacturers put a 1:12 twist on their .308's (Winchester and Sako) and others give them a 1:10 twist, like the .30-06 (Remington, Ruger). I have owned .308's with both twists, and they have all shot bullets from 150 to 180 grains with equal success. Given those bullet weights, I'm sure that other factors affect the gun's accuracy and the bullets' performance far more than the difference between a 1:10 and 1:12 twist.

I understand that the majority of bench rest shooters seem to prefer the 1:12 twist with the bullets they use, but bench rest shooting and hunting are two different activities . Bench rest shooters, by necessity, are always fooling around with all the little variables in order to wring out the best accuracy possible; plus, they usually confine t hemselves to bullets weighing around 165 to 168 grains. It's in the heavier bullets where a sharper twist might be necessary.

I think that if I wanted to load bullets heavier than 180 grains, then I would defintely choose the 1:10 twist. Conversely, if I wanted to use bullets lighter than 150 grains, I'd probably lean more to the 1:12 twist.